Will smoking past affect Obama's health?

Now that John McCain has finally released his medical records, the issue of candidates' health should be put to rest, right? Not so fast. Barack Obama's campaign has said at least some of his medical records would be released next week, and if complete, they may reveal some valuable information.

While voters should pick their candidate based on the issues, we have a right to know of any lurking health issues. Obama is young, active and looks great. But he has a documented history as a cigarette smoker. Not many people realize that even as a former smoker, he faces significantly increased risks of smoking-related diseases. These risks did not simply disappear when he quit smoking in February 2007. (Let me be clear, this is not an appeal to puritanical values — nor an endorsement of a candidate. This is about the long-term and sometimes irreversible consequences of smoking cigarettes.)

Yes, Obama claims to have quit — and by doing so, he did reduce his risk of smoking-related disease. But the science tells us that it is naive to think that quitting after years of smoking returns you to the state of health of a never-smoker. In fact, after enough smoking, some health effects are irreversible. How long and how much one smokes determines the extent of health risk after quitting.

More than half of all lung cancers are diagnosed in ex-smokers. And it's not just lung cancer. Ex-smokers face long term risks for pancreatic, esophageal, bladder, and kidney cancers, to name a few.

A 1998 study reported that the amount of fatty deposits in the carotid artery depended on total pack-years of tobacco exposure in a lifetime, not whether a patient currently smokes. A smoker's excess risk of a stroke doesn't return to that of nonsmokers until at least five, or as long as 20, years after quitting. It is possible that Obama would have to serve a hypothetical four smoke-free terms before his stroke risk returned to normal.

So how long and how much did Obama smoke? The campaign refuses to say, but we know he smoked a lot over his life. Based on accounts of his friends, we know he was smoking by the time he was a freshman at Occidental College three decades ago. He admits to having smoked up to ten cigarettes a day, but he said he usually smoked closer to four or five daily.

Most people underestimate how much they smoke, but let's take him at his word. Let's also assume he really did quit when he said he did, although he admits to having fallen off the wagon on occasion.

So he smoked for at least a quarter-century. That's more than 50,000 cigarettes — and maybe as many as 70,000.

Just because he's young, looks great and exercises doesn't mean he's completely healthy. And given what an important figure he is, to ignore his smoking history is to miss an educational opportunity.